Looking for a rhetorical term similiar to metaphor, synechdoche, metonymy etc. to describe a certain concept.

While translating a screenplay, an interesting play on words just came up. In a scene where a dying old man's bony hands are extremely prominent, he later says, "I haven't much time on my hands."

Of course, there's irony there, because he most certainly does have time on his hands, in a literal sense. But I'm struggling to come up with a way to express the idea of a parallel --or double-- meaning, especially when a metaphorical phrase contrasts or adds to something literal.

Any suggestions?